Base end structure for electric lamps or similar devices



June 14, 1966 s. c. ACKERMAN BASE END STRUCTURE FOR ELECTRIC LAMPS OR SIMILAR DEVICES Filed May 1, 1964 Irv/an hor: S t'anbeg C. AckeT-man b w torney the lamp bulb.

United States Patent 3,256,507 BASE END STRUCTURE FOR ELECTRIC LAMPS 0R SllVIILAR DEVICES Stanley C. Ackerrnan, Cleveland Heights, Ohio, assignor to General Electric Company, a corporation of New York Filed May 1, 1964, Ser. No. 364,099 6 Claims. (Cl. 339-144) This invention relates, in general, to a base end structure for electric lamps or similar devices, and more particularly to a base or metal terminal contact construction for electric lamps or similar devices of the type in which the vitreous envelope of the device is provided at one end with a protruding flat press seal portion.

Certain types of electric incandescent lamps known at present employ a so-called ribbon seal for the lamp leadin conductors wherein each conductor is formed with a thin ribbon-like portion which is sealed within a protruding flattened press seal portion on the vitreous bulb or envelope of the lamp. The flattened press seal portion of the lamp envelope is preferably formed of I-shaped transverse section, and the ribbon portions of the two lamp lead-in conductors are sealed into the flattened web portion of the press seal and terminate at their outer ends in thicker outer lead or terminal contact portions of wire or rod-like form which protrude endwise from the press seal. I v

In accordance with customary practice, it is desirable to provide such a type electric lamp with a suitable form of base construction, preferably of the so-called slide type, for permitting ready insertion of the lamp into a suitable socket. Particularly in the case, moreover, of lamps of the type which are designed to operate at exceedingly high bulb wall temperatures, such as is true for example of the Well-known iodine cycletype incandescent lamps, it is preferable in such case to employ a base of the so-called mechanical or cementless type which does not require the use of any basing cement to fasten the base in place on It is an object of my invention, therefore, to provide an electric lamp or similar device having a novel base end structure which is of simple and inexpensive construction and easy to assemble.

Another object of my invention is to provide a novel form of base structure for an electric lamp or similar de vice of the type having a vitreous envelope or bulb provided with a protruding press seal portion of I-shaped transverse section.

Still another object of my invention is to provide a base structure for an electric lamp or similar device of the character referred to above which base structure is adapted for cementless attachment to the protruding press seal portion of the vitreous envelope of the device.

Briefly stated, in accordance with one aspect of the invention, a pair of channel-shaped sheet metal base members are adapted for endwise sliding movement onto the respective side flange portions of a protruding I-shaped press seal on the vitreous envelope of anelectric lamp or similar device, the channel-shaped members snugly fitting over the side flange portions of the press seal in spaced relation thereon and having their respective sides bent toward each other to thereby lock the members in place on the press seal against sidewise removal therefrom.

In accordance with a further aspect of the invention, one or both sides of each of the channel-shaped base members are formed with outer end tab extensions which are rigidly secured, as by welding, for example, to outer end portions of the lamp lead-in conductors which protrude endwise from the press seal.

Further objects and advantages of the invention will apice incandescent lamp having a base end structure comprising the invention, the base being shown in section.

FIG. 2 is a sectional view on the line 2-2 of FIG. 1.

FIG. 3 is an end view of the base end of the lamp shown in FIG. 1, and' FIG. 4 is an exploded perspective view of the base end structure comprising the invention.

Referring to the drawing, the invention is there illustrated as embodied in an electric incandescent lamp 'comprising a hermetically sealed vitreous envelope or'bulb 1 which contains a coiled-coil tungsten filament 2 connected at its ends to respective lead-in conductors comprising inner and outer portions 3 and 4 of tungsten and molybdenum, respectively, and intermediate molybdenum foil or ribbon sections 5 which are hermetically sealed in spaced apart relation in a compressed protruding pinch seal portion 6 formed on one end of the envelope, the seal portion 6 being pressed to an I-shaped section as shown in FIG. 2 and the outer portions 4 of'the lead-in conductors protruding endwise from the press seal 6. It should be understood, however, that the invention may be embodied in any type of electrical device having a vitreous envelope 1 formed with a press seal 6 of the I-shaped section as described above.

The particular electric incandescent lamp illustrated is of the well-known iodine cycle type as described and claimed in US. Patent 2,883,571, Fridrich and Wiley, the envelope 1 for such purpose containing, in addition to a suitable gas filling such as argon, krypton or xenon at a substantial pressure of, for example, 600 mm. Hg or above, a small amount of iodine vapor which functions as a regenerative getter during lamp operation to combine with tungsten vaporized from the filament 2 onto the envelope wall to thereby form a tungsten iodide which migrates back to the vicinity of the filament where it then dissociates to redeposit tungsten onto the filament and release iodine for continuation of the cycle. Since such iodine cycle lamps ordinarily operate at relatively high envelope or bulb wall temperatures, the envelope 1 of the lamp is preferably made of a high melting point vitreous material such as fused quartz or hard glass. The coiledcoil filament 2 is arranged within the envelope 1 in U or hairpin shape as shown, and it is additionally supported at its mid-region, at the bend therein, by a supplementary U-shaped wire support 7 the legs of which are embedded and supported at their free ends in the press seal 6.

The lead-in conductors comprised of the inner and outer portions 3 and 4 and intermediate ribbon seal portions 5 are sealed through the web portion 8 of the press seal 6 inboard of the side flange portions 9 thereof and preferably symmetrically on opposite sides of the longitudinal axis of the envelope 1, with the plane of the interseal 6, the outer leads 4 are provided with enlarged rod or bar-like terminal connector or contact portions 10 which are preferably constituted of nickel and may be formed, for example, by crimping and flattening nickel sleeves onto the protruding outer lead portions 4 was to be securely fastened thereto and present flat contact surfaces 11 disposed parallel to the plane of the web portion 8 of the press seal 6.

Mounted on the press seal portion 6 of the lamp envelope 1 is a base structure according to the invention comprising a pair of channel-shaped sheet metal terminal contact members 12, preferably of stainless steel of around. .010" thickness for example, which are snugly slip-fitted over the respective side flanges 9 of the press seal 6 in spaced apart relation with the sides 13 of the respective terminal contact members facing inwardly of the press seal toward one another, as shown in FIGS. 2 and 3. Inboard of the press seal side flange portions 9, the sides 13 of the respective metal contact members 12 are bent inwardly at a slight converging angle to thereby catch behind the side flange portions 9 and thus lock the contact members firmly in place on the press seal against sidewise disengagement therefrom such as might otherwise occur upon withdrawal of the lamp from a push-in pull-out type lamp socket. To further assure against any such sidewise disengagement of the metal contact members 12 from the press seal 6, they may be additionally secured in place thereon by means of fillings 14 (FIG. 2) of a suitable lamp basing cement disposed in the spaces between the sides 13 of the metal contact members and the web 8 of the press seal 6. In the case of a high operating temperature lamp such as the previously mentioned iodine cycle incandescent lamp, the basing cement 14 should be of a high heat-resistant type such as disclosed, for example, in US. Patent 3,080,243, Vodicka. To provide a spring friction grip of the lamp in its socket such as to hold it firmly in place therein, the U-shaped metal contact members 12 may be formed with bowed-out spring tongues 15 struck out of their web portions 16 for spring pressure engagement with the lamp socket.

At their outer ends, the sides 13 of each metal contact member 12 are extended and offset toward one another to form small locating shoulders 17 thereon and a pair of opposed connector tab extensions 18 for connection to the protruding contact portions 19 of the outer leads 4. The locating shoulders 17 serve as limiting stops for engagement with the outer end of the press seal 6, during the sliding assembly of the metal contact member 12 onto the press seal 6 as shown in FIG. 4, to thereby locate the metal contact member in proper endwise position on the press seal. The connector tab extensions 18 on each U-shaped channel contact member 12 are disposed in spaced parallel relation to each other and ar parallel to and symmetrically located on opposite sides of the longitudinal axis plane of the U-shaped channel member so as to be in position to receive therebetween the outer end contact portions 10 of the outer leads 4 upon completion of the sliding assembly movement of the contact members 12 onto the press seal 6 of the lamp. As initially formed, each cooperating pair of connector tab extensions 18 are spaced apart a distance slightly greater than the thickness of the flattened outer end contact portions 10 of the outer leads 4 so as to freely receive the said contact portions therebetween during the sliding placement or assembly of the contact member 12 over the press seal 6 of the lamp. Upon completion of the sliding assembly movement of the metal contact members 12 onto the press seal 6, as determined by the engagement of the locating shoulders 17 thereon with the outer end of the press seal, the connector tab extensions 18 on the contact members 12 are then rigidly secured to the outer end contact portions 10 of the outer leads 4 in a suitable manner as, for example, by clamping them to the flattened surfaces 11 of the said contact portions 10 and preferably, in addition, welding them thereto, to thereby electrically connect the metal contact members 12 to the lead-in conductors of the lamp. In the event the metal contact members 12 are additionally provided with fillings 14 of basing cement, the assembled lamp envelope 1 and metal contact members 12 are in such case then heated to the temperature and for the required period of time necessary to effect the curing of the basing cement.

From the above description, it will be apparent that I have provided a novel base structure, of very simple and inexpensive construction and extremely easy to assemble, for electric lamps and similar devices of the type having their envelopes 1 formed with protruding press seals 6 of I-shaped section. The only operational steps required for assembly of the base structure on the lamp envelope 1 are the sliding placement of the metal channel members 12 on the press seal 6 of the lamp envelope 1 followed by the clamping and/ or welding of the tab extensions 18 to the protruding outer contact portions 10 of the lamp lead-in conductors. Moreover, because of its attachment to the I-shaped press seal portion 6 of the lamp envelope 1 by mechanical means such as obviates the need for any basing cement, the base end structure according to the invention is therefore particularly adapted for use on electric incandescent lamps of such I-shaped press seal construction which normally operate at rela- .tively high envelope wall temperatures such as, for example, the well-known iodine cycle type incandescent lamps.

Although a preferred embodiment of my invention has been disclosed, it will be understood that the invention is not to be limited to the specific construction and arrangement of parts shown, but that they may be widely modified within the spirit and scope of my invention as defined by the appended claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

'1. An electrical device comprising a sealed envelope of vitreous material having a protruding press seal portion of generally I-shaped transverse section, at least-one lead-in conductor hermetically sealed through said press seal portion and protruding endwise therefrom, and a metal terminal contact mounted on said press seal and comprising a channel-shaped sheet metal member having a snug slip-fit over one of the side flanges of said press seal and having its opposed sides bent toward one another inboard of said one side flange to thereby lock the said contact member firmly in place on said press seal against sidewise disengagement therefrom, at least one of the opposite sides of said channel-shaped contact member having an outer end tab extension projecting endwise therefrom beyond the end of said press seal and rigidly secured to the protruding outer end portion of said lead-in conductor.

2. An electrical device comprising a sealed envelope of vitreous material having a protruding press seal portion of generally I-shaped transverse section, at least one lead-in conductor hermetically sealed through said press seal portion and protruding endwise therefrom, and a metal terminal contact mounted on said press seal and comprising a channel-shaped sheet metal member having a snug slip-fit over one of the side flanges of said press seal and having its opposed sides bent toward one another inboard of said one side flange to thereby lock the said contact member firmly in place on said press seal against sidewise disengagement therefrom, the opposite sides of said channel-shaped contact member having outer end tab extensions projecting endwise therefrom beyond the end of said press seal and clamped against opposite sides of and rigidly secured to the protruding outer end portion of said lead-in conductor.

3. An electrical device as specified in claim 1 wherein the said channel-shaped contact member is additionally secured in place on said press seal by a quantity of basing cement disposed between the opposite sides of said contact member and the web of said press seal.

4. An electrical device comprising a sealed envelope of vitreous material having a protruding press seal portion of generally I-shaped transverse section, a pair of lead-in conductors hermetically sealed through the web portion of said press seal in spaced relation to one another and protruding endwise therefrom, and a pair of terminal contacts mounted on said press seal in spaced relation and comprising channel-shaped sheet metal members snugly slip-fitted over the respective side flanges of said press seal with the opposed sides of each of said contact members bent toward one another inboard of the respective side flange of said press seal to thereby lock the contact member firmly in place thereon against sidewise disengagement therefrom, the opposite sides of each of said channel-shaped contact members having outer end tab extensions projecting endwise therefrom beyond the end of said press seal and clamped against opposite sides of and rig'dly secured to the protruding outer end portions of respective ones of said lead-in conductors.

5. An electrical device as specified in claim 4 wherein the opposed sides of each of said contact members are bent at an angle to converge toward one another inboard of the respective side flange of said press seal so as to lock'the contact member firmly in place thereon against sidewise disengagement therefrom.

6. An electrical device as specified in claim 4 wherein the said channel-shaped contact members are additionally secured in place on said press seal by a quantity of basing cement disposed between the web of said press seal and the opposite sides of the respective contact members.

References Cited by the Examiner UNITED STATES PATENTS 1,469,208 10/1923 Bohlman 339144 X 3,001,097 9/1961 Smialek 339144 X 3,093,768 6/1963 Ayres 339-144 PATRICK A. CLIFFORD, Primary Examiner.

W. D. MILLER, Assistant Examiner. 

1. AN ELECTRICAL DEVICE COMPRISING A SEALED ENVELOPE OF VITREOUS MATERIAL HAVING A PROTRUDING PRESS SEAL PORTION OF GENERALLY I-SHAPED TRANSVERSE SECTION, AT LEAST ONE LEAD-IN CONDUCTOR HERMETICALLY SEALED THROUGH SAID PRESS SEAL PORTION AND PROTRUDING ENDWISE THEREFROM, AND A METAL TERMINAL CONTACT MOUNTED ON SAID PRESS SEAL AND COMPRISING A CHANNEL-SHAPED SHEET METAL MEMBER HAVING A SNUG SLIP-FIT OVER ONE OF THE SIDE FLANGES OF SAID PRESS SEAL AND HAVING ITS OPPOSED SIDES BENT TOWARD ONE ANOTHER INBOARD OF SAID ONE SIDE FLANGE TO THEREBY LOCK THE SAID CONTACT MEMBER FIRMLY IN PLACE ON SAID PRESS SEAL AGAINST SIDEWISE DISENGAGEMENT THEREFROM, AT LEAST ONE OF THE OPPOSITE SIDES OF SAID CHANNEL-SHAPED CONTACT MEMBER HAVING AN OUTER END TAB EXTENSION PROJECTING ENDWISE THEREFROM BEYOND THE END OF SAID PRESS SEAL AND RIGIDLY SECURED TO THE PROTRUDING OUTER END PORTION OF SAID LEAD-IN CONDUCTOR. 